The REPIPE code, a post-processor of the transient thermal-hydraulic computer code RELAP4/ MOD5, was developed to retrieve relevant data from RELAP4 and calculate the time-dependent force exerted on the piping system subjected to pipe rupture. The package of RELAP4/REPIPE forms a tool for both thermal-hydraulic and piping analysis. Both analytical and experimental data of different fluid conditions were used to verify the RELAP4/ REPIPE package. Code-data comparison indicated an overall good code performance.